1. Field
This document relates to an apparatus and method of supplying power to an electronic device.
2. Related Art
Generally, power supplies for electronic devices such as mobile phones, personal digital assistants (PDAs), and laptop computers include a power management integrated circuit (PMIC) 10 as shown in FIG. 1.
The PMIC 10 includes a controller 100, a plurality of DC/DC converters 1101, 1102, and 1103, and a plurality of low-dropout (LDO) regulators 1201, 1202, and 1203.
The controller 100 enables the plurality of DC/DC converters and LDO regulators to have a predetermined initial (power) value when the electronic device is system-booted.
Accordingly, main power supplied to the PMIC 10 is converted to different output power components. For example, main power of 3.7V/1500 mA supplied from a battery is converted to DCO1 (DC output1) power of 2.5V/450 mA by the first DC/DC converter 1101.
The main power is also converted to DCO2 power of 3.3V/1000 mA by the second DC/DC converter 1102, and to DCO3 power of 1.3V/500 mA by the third DC/DC converter 1103.
The main power of 3.7V/1500 mA is converted to LDO1 power of 1.8V/100 mA by the first LDO regulator 1201, LDO2 power of 1.5V/200 mA by the second LDO regulator 1202, and LDO3 power of 1.2V/150 mA by the third LDO regulator 1203.
Each converted output power is supplied to each different load as operating power. The DC/DC converter is a voltage converting device for making an output voltage higher or lower than an input voltage. A converter for converting a low input voltage to a higher output voltage is called “step-up converter” and a converter for converting a high input voltage to a lower output voltage is called “step-down converter”.
For example, a step-up converter employs a buck DC/DC converter and a step-down converter employs a boost converter. In general, DC/DC converters are classified into PWM (Pulse Width Modulation) type DC/DC converters and PFM (Pulse Frequency Modulation) type DC/DC converters based on switching scheme.
Meanwhile, LDO regulators have the advantage of being capable of supplying a stable voltage having reduced ripple components, as is widely known. In the case of a high input voltage, however, significant power loss may occur while the high input voltage is converted to a lower output voltage.